Assessing the post-marketing safety of authorized generic drug products More than 8 out of every 10 prescriptions dispensed in the US are for generic drugs, but generics account for only about 20% of spending on prescription drugs in the US. As compared to brand- name versions, less costly generic drugs reduce healthcare spending and promote medication adherence. In recent work, we have found that improved medication adherence associated with generic drugs improves patient health outcomes. Despite the cost and potential health benefits of generic drugs, negative perceptions about generic drugs persist among patients and healthcare providers alike. A number of observational studies have found that many patients who switch from a brand-name drug to a generic switch back to the brand-name version. High switchback rates have been attributed to poor patient experience with the generic product. However, many factors, including negative perceptions, can affect whether patients switch back from a generic to a brand- name medication. Negative perceptions can also affect substitution rates, but this has not yet been empirically investigated. Authorized generics, which are brand-name drugs that are marketed, sold, or distributed as generic medications, provide a clever opportunity to examine the extent to which negative perceptions of generic drugs affect acceptance and use of these beneficial treatments since authorized generics are chemically-identical to brand-name versions but may differ in trade dress; that is, they are brand-name versions that appear as though they are generics and have costs similar to generics. The objective of this project is to build on our prior and ongoing work in post-marketing surveillance of generic drugs to continue to develop new methods to monitor the safety, effectiveness, and substitution patterns of generic medications. The aims of this project are to: (1) compare substitution and switchback rates, adherence, medical utilization, and clinical outcomes between authorized generic and other generic versions of model drug products and between other generic versions and brand versions of these drugs; (2) analyze FDA Adverse Event Reporting System (FAERS) data and the medical and gray literature to assess experiences with authorized generic products and whether negative perceptions of generics affects adverse event reporting; and (3) analyze national survey data to assess healthcare providers' knowledge of and experience with authorized generics.